Field of the Invention
The present invention relates to a method and station for filling gas tanks.
More particularly, the invention relates to a method of filling a tank with pressurized hydrogen via a filling station comprising at least one buffer container and a fluid circuit connected to said at least one buffer container, the circuit of the filling station comprising a first end connected to at least one source of gaseous hydrogen for carrying out the filling of the at least one buffer container with gas originating from the source, the circuit comprising a second end equipped with a transfer pipe intended to be removably connected to the tank to be filled, in order to fill the latter with hydrogen originating from the at least one buffer container, the method comprising a step of purifying the hydrogen supplied by the source in a purification component before it is transferred to the at least one buffer container, the circuit of the filling station additionally comprising at least one compression component for compressing pressurized gas in order to fill the at least one buffer container.
Related Art
The fast filling (typically in less than 15 minutes) of tanks of fuel gas (hydrogen in particular) at high pressure (300 to 800 bar for example) is generally carried out by successive equalizations between buffer containers at high pressure (for example 200, 300, 450 or 850 bar) and the tank to be filled. This filling may, where necessary, be complemented or supplemented by one or more compressors.
In order to limit the increase in temperature in the tanks due to the adiabatic nature of the compression, the fuel gas is cooled, for example to a temperature of the order or −40° C. before it enters the tank. This cooling is generally carried out via a heat exchanger supplied with a refrigerant or cryogenic fluid. These methods are described abundantly in the literature.
Reference may for example be made to documents FR 2919375 A1, FR 2973858 A1 and FR 2919375 A1 that describe filling stations to which the present invention may apply.
The fuel cells in particular of “PEMFC” type installed on board vehicles that use this hydrogen fuel must be supplied with a very pure hydrogen. A wealth of literature has described the impacts of impurities (such as water, CO, H2S) in the hydrogen on the performance and service life of the fuel cells. Strict standards have thus been developed to ensure that the hydrogen delivered to the tanks does not damage the cells (cf. for example the ISO 14687-2 standard).
The known and relatively inexpensive industrial manufacturing processes do not make it possible to ensure such a degree of purity continuously.
In order to guarantee a degree of purity of the hydrogen, it may be necessary to add, upstream of the filling stations, extremely expensive purification steps, such as purifications over a bed of adsorbent operating at cryogenic temperature or palladium membranes.
Another solution consists in supplying the filling station with hydrogen that is liquid, and therefore very pure, or via electrolyzers. These solutions are however expensive.